The field of use for the present invention and the above-noted prior art is for the testing of drug-dissolution rates of tablets and the like when placed in a dissolution vessel containing stirred water--continuously stirred by paddles mounted on the lower end of a downwardly lineally-extending revolvable shaft from a stirrer motor. The government regulators and inspectors for drug-tablet producing manufacturers require that the downwardly extending lineally-extending revolvable shaft (that has paddle-blades mounted on its bottom) always be the same position, centered within the mouth of the vessel, in order to prevent undetected variations in dissolution [if the paddle stirring varied from test to test, different inaccurate dissolution rates would be registered incorrectly].
Of equal or more importance, the vessel that normally looks-Like an over-sized test-tube, actually a water-containing vessel about 8 inches deep with a round hemispherical bottom so that there are no dead-spaces of liquid around the bottom, must be centered, as hopefully mounted and thereafter maintained against effects of vibrations or other contributing factors that could lead in accidental non-alignment, within a dissolution vessel-support--relative to the central position of the downwardly-extending paddle-stirring columnar-shaft (above-noted) of the stirrer.
Apart from the possibility that initial alignment heretofore by prior art apparatus and methods of use thereof to attempt to secure proper alignment, in fact often failed in the attempt, even when reasonably aligned, the stirrer shaft is sometimes removed and reinserted. While the mere repositioning or remounting of the revolvable mixer blade-containing shaft might result in misalignment to a non-aligned state, there also exists a real possibility that the mere cumbersom handling or dropping of the blade-containing shaft onto a counter-top could cause the very sensitive shaft to become bent slightly--such slight bending being more than enough to totally destroy any possibility of alignment, and such bent or distorted bladed-shaft thereafter when revolved causing vibrating and the concurrent non-controlled varying erratic stirring of the water contents in the dissolution vessel--a condition unacceptable to government regulators and inspectors.